Young boy, five years old. A school play requires all the boys and girls to wear white tights. The teacher recommends girls' pantyhose. The boys shouldn't mind, since they're still too young to have much of a sexual identity. So the boy's mother buys him the tights, and he wears them the night of the school play. All the parents love the show, and our little boy goes home happy and appreciated. He likes the feel of the stockings, and the adulation he got while wearing them. He is aware that they are meant only for girls. He asks before his parents tuck him in if he can wear them as pajamas. They tell him absolutely not, because they have to return them to the store, and besides, they're for girls, not boys.
Our boy has an older sister. He has taken an interest that he cannot understand in her clothes. He knows that he is not allowed to wear them, so he lets it rest for a few years.
By the time he is nine, he feels intense urges to put on stockings again. He has felt them for many years, but never dared. Now he gets the idea to plunder the laundry basket, steal some stockings, and try them on in private at night. He loves the silkiness of them. But he's afraid to put them on. He's afraid that they'll turn him into a girl. Under no circumstances are they to touch his penis. The first few thefts, he doesn't even have the courage to wear them. Finally, he dares, and puts them on over his underwear.
They're just like socks, he thinks, only so thin and soft, and they go all the way up my thigh, all the way over my crotch, to my waist. This is what it feels like to wear girl socks. It feels so very nice. Now my legs look like those of the pin-up girls in daddy's magazines, and those pretty girls I can't bear to look at on TV. They make me feel so good. But they're girl clothes, and I'm not supposed to wear them. They're probably going to turn me into a girl. I'd better take them off before it's too late.
He takes them off carefully and rubs his little dick to thoughts of older girls in stockings like these, and the short ones that come up to the thighs, and panties and bikinis…
Weeks later, he does it again. And again a week later. He does it twice the week after that.
Pretty soon, he's not taking them off anymore. Then he's not wearing his own underwear to protect himself from them. He knows he's turning into a girl, and that's what he loves about it: he imagines himself one day able to wear lingerie.
But his sister finds out. She sees him taking her stockings, but hides, and notes what he's doing. She can tell immediately what's going on. She waits for the opportune moment, and then she blackmails him. He fearfully obliges.
For her viewing pleasure, she has him put on her pretty little panties and her training bra. Then her bathing suit. He can't take it. He's not ready for this much girlhood, even though he's been fantasizing about it for months. She makes him primp in the mirror. At his age, he looks just like a girl, except for the hard lump at his crotch.
Now he knows he's ruined. And he loves it. He borrows her panties every day. He masturbates in her bathing suit. He can't wait till she gets old enough for lingerie. He wants to wear a garter belt and fishnet stockings and a corset.
So his sister puts her foot down. No way, she says, you're going to have to get your own. I can't have you wearing my panties all the time.
He begins to use his allowance money to buy girls' clothes instead of toys. He gets her to buy it for him, at first. Then she refuses even this. So he must buy it all himself. So he does, with great embarrassment. Until he gets used to it. Now he buys bikinis, which even his sister hasn't dared to wear. He buys cheap lingerie. He wears his own panties when he goes on shopping excursions. He is turning into a girl. He can't help himself.
So finally, he reveals his secret to his parents. He has decided to become a girl. He has chosen the right time in his life, since he still hasn't reached puberty. So he gets hormone replacement, and develops in his teens as a girl.